Partial Packingslip using code in ax 2012

static void Job49(Args _args)
{
   salesLine salesLine;
   salesFormLetter salesFormLetter;
   SalesTable salestable;
   ;
   ttsbegin;
   //update Sales Line
   salestable = salestable::find('DSB-0000001089');
   salesLine = SalesLine::find('DSB-0000001089', 1, true);  // find the item id
   salesLine.SalesDeliverNow   = 1;
   salesLine.setInventDeliverNow();
   salesLine.doUpdate();
   //Post the delivery note
   salesFormLetter = SalesFormLetter::construct(DocumentStatus::PackingSlip);
   //salesFormLetter.progressHide();                                // Hide the progress bar.
   salesFormLetter.update(salesTable,                             // SalesTable
                       SystemDateGet(),                        // Delivery date
                       SalesUpdate::DeliverNow,                // Quantity to update (SpecQty)
                       AccountOrder::None,                     // AccountOrder
                       false,                                  // Proforma only?
                       false);                                 // Printout?
    ttsCommit;

}